Compound engine



(No Model.)

3 Sheets-Sheet 1. P. W. DEAN.

COMPOUND ENGINE. No. 433,164.

Patnted July 29, 1890.

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(No Model.) 3 Sheets-Sheet 2.

F. W. DEAN.

COMPOUND ENGINE.

No. 433,164. Patented July 29, 1890.

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(No Model.) 3 Sheets-Sheet 3,

F. W. DEAN. Y

COMPOUND ENGINE.

No. 433,164. Patented July 29,1890.

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UNITED STATES PATENT OFFICE.

FRANCIS \V. DEAN, OF CAMBRIDGE, MASSACHUSETTS.

COMPOUND ENGINE.

SPECIFItCATIOlfLforming part of Letters Patent No. 433,164, dated July29, 1890. Application filed May 29, 1890. Serial No. 353,579. (Nomodel.)

To all whom it may concern.-

Be it known that I, FRANCIS W. DEAN, of Cambridge, in the county ofMiddlesex and State of Massachusetts, have invented certain new anduseful Improvements in Compound Engines, of which the following, takenin connection with the accompanying drawings, is a specification.

My invention relates to compound engines of that class in which instarting live steam is simultaneously admitted to both cylinders inorder to obtain greater pressure at starting, and also to obviate thedifficulty sometimes met of having to apply manual power to start theengine when steam is admitted first to the high-pressure cylinder only,and the high-pressure crank happens to be on one of its dead-centers.

The objects of my invention are to automatically regulate the admissionof live steam to the low-pressure cylinder in starting, and toautomatically cut off the supply of live steam to said low-pressurecylinder when the crank-shaft commences to revolve; and it consists incertain novel features of construction, arrangement, and combination ofparts, which will be readily understood by reference to the descriptionof the drawings and to the claims hereinafter given, and in which myinvention is clearly. pointed out.

Figure l of the drawings is a vertical transverse section through thesn1oke-box of a locomotive-boiler and the two steam-cylinders of acompound engine illustrating my invention on line 00 so on Fig. 2. Fig.2 is a plan of the saddles and the steam-cylinders with the steam-chestsand covers removed. Fig. 3 is a central longitudinal section through aportion of the boiler-shell on line 1 1 on Fig. 1, and through a portionof the steam-pipe leading from the high-pressure cylinder to thelow-pressure cylinder on line 2 2 on Fig. 1. Fig. 4 is a plan of thepipe and receivers connecting the two cylinders as it would appear ifstraightened out so as to lie in a flat plane. Fig. 5 is an elevation ofthe same receivers and pipe when in their normal or bent condition andviewed from a position at the left of Fig. 1. Fig. 6 is a transversesection of one of the receivers on line 3 3 on Fig. 4.. Fig. 7 is a planof the converting-valve casing. Fig. 8 is a vertical section on line 4 4on Fig. '7.

Fig. 9 is an elevation of the flanged innerface of said converting-valvecasing, and Fig. 10 is a plan of the lower head of said valve-cas' ingand inlet-pipe for live steam.

My invention is illustrated in the accompanying drawings as applied to alocomotive, only so much of said engine being shown as is necessary toillustrate my invention; but the principal features of my invention areequally as applicable to stationary as to locomotive engines.

In the drawings, A represents the shell of the locomotive-boiler; A, thetube-sheet at the rear of the smoke-box.

B is the high-pressure cylinder; 3, its saddle; B its steam -chest, andB the steamchest cover.

C is the low-pressure cylinder, C its saddle, C its steam-chest, and Cthe steam-chest cover.

D is the steam-supply pipe, through which live steam passes from thesteam-dome to the steam-chest of the high-pressure cylinder.

B" is the exhaust-passage of the high-pressure cylinder, to the upperend of which is connected the pipe E, which has its upper end curvedtoward the front of the engine audits open end inclined to formavalve-seat, as will be presently explained. The curved upper end of thepipeE projects into the lower end of the pipe E, which is firmly securedwith a steanrtight joint to the collar a on said pipe E, as shown inFig. The pipe E is forked or divided at G into two branches E and E tothe upper ends of which are bolted the en larged receiver-pipes E and Erespectively, the lower ends of which communicate, respectively, withthe supply-passages F and F, leading to the interior of the low-pressuresteam-chest 0*, as shown in Figs. 1 and 2.

G is the exhaust-passage of the low-pressure cylinder communicating atits upper end with the exhaust-pipe G, of usual construction.

The pipe E has a branch opening in its side just above its connection tothe pipe E, surrounded by a flange, the outer face of which is inclinedto a vertical plane, with its upper portion farthest from the centerline of said pipe, said opening being closed by the cover E providedupon its inner face with the annular valve-seat Z), preferably in theform of a removable ring of asbestus, upon which the annular rib c onthe interceptingvalve II is seatedwhen steam is passing from the high-pressure cylinder to the low-pressure cylinder through the pipes E,-E, E and E and the receivers E and E The valve H is mounted upon thepivot-pin d, set in the pipe E, and has secured to its inner face'anannular packing e, preferably of asbestus, which, when said valve H ismoved away from the seat b, rests upon the inclined upper end of thepipe E and closes communication between the pipes E and E. The cover Ehas an opening f through its center, into which is screwed one end of apipe g, the opposite end of which communicates with the interior of theconverting-valve casing I, secured to the exterior of the smoke-box, asshown in Fig.

1. The casing I has its upper end closed by the cap I, in the center ofwhich is to be screwed an oil-cup, (not shown,) and its lower end hassecured thereto the elbow-pipe 1 the upper end of which forms avalve-seat g, upon which the valve J rests-when in its normal position.

The interior of the casing I is dividedinto two chambers I and I by thehorizontal partition I in the center of which is formed a bearing forthe valve-rod J, which extends some distance above said bearing, and hasfirmly secured thereon the piston J of considerably larger area than thevalve J and fitted to work steam-tight in the chamber I as shown. lip h,projecting downward therefrom to serve as a valve-seat, against whichthe upper side of the valve J is seated when it is forced upward by livesteam entering through the pipe I and limit its upward movement. Thelower end of the pipe I communicates through the pipe h with theinterior of the steam-supply pipe D, as shown in Figs. 1 and 3. The upper part of the chamber I of the convertingvalve casing I is connectedby the pipe 7L2 with the interior of the pipe E, as shown in Figs. 1 and3, and the lower part of said chamber has inserted therein at z awaste-pipe to convey away any water of condensation which maybedeposited therein, or a ny'steam that may find its way past thepartition I between the valve-rod J and its hearing. The receivers E andE? are strengthened by means of the partitions j j, one or more, asshown in Fig. 6. V

The operation of my invention is as follows: The parts being in thepositions shown in the drawings and it being desired to start the'engine, the engineer opens the throttle-valve, when live steam passesthrough the pipe D to the high-pressure steam-chest and at the same timelive steam passes through thepipes h and I to the under side of thevalve J, which it moves upward till its upper packing-ring is seatedagainst the annular lip h, thus opening a free passage of the live steamthrough the pipe 9 to the center of the intercepting-valve H, which itmoves to the right of Fig. 3, till it is seated upon the upper end Thepartition I has an annular of the pipe E, so as to close it steam-tight,the live steam continuing through the pipes E E E receivers E and E andthe supplypassages F and F to the interior of the lowpressuresteam-chest. By this means the engine is sure to start at once,even-though the crank of the high-pressure engine should have beenstopped upon its dead-center. When the high-pressure cylinder exhausts,a portion of the exhaust-steam passes through the pipe 7L2 to theinterior of the chamber 1, above the piston J and by virtue of thedifference of area between said piston and the valve J said valve J willbe moved downward upon its seat on the endot' the pipe I and the livesteam is shut olf from the interior of the converting-valve casing I andremains so shut off until the next time it becomes necessary to startthe engine. The valve J has secured to its under side an annularpacking-ring 70, preferably of asbestus, to rest upon the seat g whensaid valve is in its normal position, and tovits upperside a similarring k to co-operate with the seat h to limit its upward movement, saidpacking-ring also serving to lessen the shock of the blow when saidvalve is suddenly moved upward.

The advantages of this invention are the increased effectiveness of thelow-pressure engine due to the greater area of the pipes leading fromthe high to the low pressure cylinders exposed to the hot gases,cheap'ness of con struction, and effectiveness in operation.

I claim 1. In combination with the high and low pressure cylinders of acompound engine, their steam-chests and steam passages, a communicatingpassage between said cylinders, comprising a forked pipe having a singleopening communicating with the exhaust of the high-pressure cylinder,and two branches therefrom having an aggregatearea of cross section andexterior surface greater than the initial or single portion of saidpipe, as set forth.

2. In combination with the high and low pressure cylinders of a compoundengine,

their steam-chests and steam-passages, a communicating pipe connectingsaid cylinders, comprising a single pipe for a short distance at one endand two parallel branches forking therefrom and having an aggregate areain cross-section much greater than the area of the single initialportion thereof, said branches having a portion of their length expandedto a much larger area of cross-section to form receivers, as described.

3. In combination with the high and low pressure cylinders of "acompound engine, their steam-chests and steam-passages, a pipecommunicating with the exhaust-passage of the high-pressure cylinder atone end and having its other end curved and terminating in an inclinedplane and provided with a collar below said inclined end, a second pipeinelosing said curved and inclined end and secured to said collar andprovided with a side opening, abonnet or cover for closing said opening,having an annular valve-seat upon its inner face, a clapper-valvepivoted within said second pipe in position to be seated upon thevalve-seat on the inner face of said cover, or upon the oblique upperend of the first pipe, the converting-valve J, its casing I, the pistonJ the pipe D, for supplying live steam to the high-pressure steam-chest,the pipes h and I connecting the interior of the pipe D With the underside of said valve J, the pipe g, connecting the interior of the chamber1 of the converting-valve casing with the interior of the pipe E, andthe pipe 7L2, connecting the interior of the pipe E with the interior ofthe chamber I" above the piston J substantially as described.

4. In a compound engine, the combination, with the high and low pressurecylinders and a steam-pipe connecting said cylinders, of anintercepting-valve comprising two seats arranged at an angle to eachother and each inclined from a perpendicular plane in oppositedirections, with their lower sides nearest to each other, and aclapper-valve mounted upon a pivotal axis between said seats andconstructed and arranged to be alternately moved in opposite directionsby the pressure of steam, and to rest upon and close the pasthe flow ofsteam is through one or the other of said seats.

5. In combination with the high and low pressure cylinders of a compoundengine, the pipe E, having its upper end curved and cut oblique to itsaxis to form a valve-seat, the pipe E, constructed and arranged toinclose the curved oblique upper end of said pipe E, and provided withalateral opening closed by a removable bonnet, an annular seat on theinner face of said bonnet inclined from a perpendicular plane in adirection the opposite of the plane of inclination of the oblique end ofthe pipe E, a clapper-valve pivoted between said two seatsin a positionto co-operate with each of said seats and to be held thereto by thepressure of steam, assisted by the force of gravity, and the pipe 9 forad mitting live steam through said bonnet and closing said valve on theend of said pipe E.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing Witnesses, on this 24th day of May, A. D.1890.

FRANCIS \V. DEAN.

\Vitnesses:

N. Q'LOMBARD, VALTER E. LOMBARD.

